The subject invention generally relates to Digital-to-Analog (D-to-A) converters and particularly to D-to-A converters each employing only a single field effect device.
Present day electronic applications often require that analog signals be provided in response to digital codes. Such analog signals might have magnitudes that are representative of the digital codes, for example. More specifically, an analog signal of a particular magnitude might be required in response to a digital code or number of 001, for instance. The magnitude of the analog signal might further be required to progressively increase as the digital number increases, for instance, as follows: 010, 011, 111, etc. Monolithic Microwave Integrated Circuits (MMIC) applications utilizing gallium arsenide semiconductor material require such D-to-A circuits. D to A converter circuits are utilized in a multitude of applications including those for communications systems, satellites, computers, control systems, etc.
Prior art D-to-A converter circuits often include a plurality of active and/or passive devices in either discrete or integrated circuit form. Such converters therefore tend to be too expensive to fabricate, take up too much space, and/or have an unduly high failure rate for some applications. Also, some complex prior art D-to-A circuits tend to operate too slowly for some requirements.